This invention is related to the power generation industry and, more particularly, to the field of electrical power generators.
In the power generation industry, power generators have an exciter positioned adjacent thereto to provide excitation to the power generators. These exciters conventionally include one or more high power diodes which each have two terminals and exhibit a nonlinear voltage-current characteristic. The diodes generally permit current to flow in one direction but inhibit current flow in the other direction. The diodes, for example, can be used to rectify voltage and to assist in the conversion of alternating current to direct current with the power generation system. Examples of such diodes in association with a brushless exciter can be seen in U.S. Pat. No. 5,093,597 by Hughes titled xe2x80x9cBrushless Exciter Saturable Reactor Diode Snubberxe2x80x9d and U.S. Pat. No. 4,745,315 by Terry, Jr. et al. titled xe2x80x9cBrushless Exciter With Zero-Gravity Rectifier Assembly.xe2x80x9d Also, an example of a diode for a rotor can be seen in U.S. Pat. No. 5,191,248 by Huss titled xe2x80x9cConnection For Rotating Diode Package.xe2x80x9d
Diodes within a power generation system, however, due to deterioration over time, sudden unanticipated voltage or other electrical conditions, or other system conditions can rupture or become otherwise damaged. During rupture or other damage conditions, diode material which forms portions of the diode can be ejected, sprayed, or otherwise be disbursed from the diode and cause problems within the power generation system (see, e.g., FIG. 4). These effects are particularly troublesome in conjunction with rotating rectifiers. For example, molten material attributed to the diode rupturing near a metal-electric junction can be ejected and cause phase-to-phase arcing within a system, e.g., when the diode is mounted to a diode wheel of a brushless exciter.
In view of the foregoing, the present invention advantageously provides a power generation system and associated methods having a diode support and rupture containment device for supporting a diode and containing diode material within the confines of the containment device which would otherwise be ejected, sprayed, or travel away from the diode and cause damage to the power generation system and other electrical devices in the vicinity. The present invention also advantageously provides an exciter, such as a brushless exciter, which has a diode support and rupture containment device associated therewith which contains molten material ejected from a diode within the confines of the device.
The present invention additionally provides a diode support and rupture containment device which easily mounts adjacent a diode so that access to the diode for inspection, cleaning, or other associated maintenance can be achieved, which has insulating qualities and strength to resist high temperature material being ejected or sprayed during diode rupture, and which prevents damage to other portions of a power generation system in the event a diode ruptures or is otherwise damaged. The diode support and rupture containment device is also advantageously relatively inexpensive, easily retrofitable within a power generation system, and provides support for the ceramic or insulative case of a high voltage diode. The present invention further provides methods of containing diode material, e.g., ejected molten material, in the event a diode ruptures or is otherwise damaged.
More particularly, a power generator system is provided having a power generator and an exciter for excitation of the power generator. The exciter preferably includes a diode wheel. The diode wheel has rotating support structure, a plurality of diodes mounted to the structure, and plurality of diode support and rupture containment devices each positioned adjacent a respective one of the plurality of diodes to support the diode and contain the diode within the confines thereof in the event the diode ruptures. Each of the diode support and rupture containment devices preferably includes a pair of spaced-apart containment members having the diode positioned therebetween.
Advantageously, each of the containment members is preferably formed of an insulating material and has a substantially annular shape to thereby define an insulative disc. The insulating material is preferably strong enough to resist the temperature of the molten material ejected from a diode such as when material contacts a metal-electric junction where the diode is connected. This containment, for example, advantageously prevents phase-to-phase arcing in diode mount assemblies such as in the diode wheels of brushless exciters.
The present invention also provides a method of containing material ejected from a diode of a power generation system. The method preferably includes pivotally connecting a rupture containment device to a diode mounting region and adjacent a diode of the power generation system. The rupture containment device includes at least one rupture containment member formed of an insulating material. The step of pivotally connecting the rupture containment device can advantageously include positioning at least one end of the at least one rupture containment member adjacent one end of the diode and positioning another end of the at least one rupture containment member adjacent another end of the diode. The at least one rupture containment member, for example, can advantageously include a pair of rupture containment members. Each of the rupture containment members preferably has a substantially annular shape so that the rupture containment member defines an insulative disc.